1. Field of the Invention
The present invention relates to an EL display device comprising an EL element, which is constructed of a light emitting organic material capable of obtaining EL (Electro Luminescence) (hereinafter referred to as organic EL material) sandwiched between an anode and a cathode, that is formed on a substrate, and to a method of manufacturing an electronic device (electronic equipment) having the El display device as a display portion (a display or a display monitor). It is to be noted that the above-mentioned EL display device is also referred to as OLED (Organic Light Emitting Diodes).
2. Description of the Related Art
In recent years, the development of a display device (EL display device) employing an EL element as a self-emissive element that utilizes the EL phenomenon of a light emitting organic material is proceeding. Since the EL display device is a self-emissive type, it does not need a backlight such as the liquid crystal display device. Furthermore, because the viewing angle of EL display devices is wider, it is perceived as a prospective display portion of mobile equipment for use outdoors.
There are two types of EL display devices, the passive type (simple matrix type) and the active type (active matrix type). Developments for both types of EL display devices are being actively carried out. In particular, the active matrix EL display device is currently attracting much attention. Researches are being made on low molecular organic EL materials and high molecular organic EL materials (organic polymer EL materials) as to organic EL materials for forming a light emitting layer which can be regarded as the core of the EL element. High molecular organic EL materials are receiving much attention because they are easier to deal with than low molecular organic EL materials and have high heat resistant characteristics.
As a film deposition method of high molecular organic EL materials, the ink-jet method proposed by Seiko Epson, Co. Ltd. is considered a favorable method. Japanese Patent Application Laid-open No. Hei 10-12377, Japanese Patent Application Laid-open No. Hei 10-153967, and Japanese Patent Application Laid-open No. Hei 11-54270 etc. may be referred to regarding this technique.
However, in the ink-jet method, the high molecular organic EL material is sprayed on the application surface. Hence, if the distance between the application surface and the nozzle of the ink-jet head is not set appropriately, drops of solution will be shot to parts that the application is not necessary, resulting in the occurrence of a problem what is known as an aviation curve. Note that details regarding the aviation curve are disclosed in the above-mentioned Japanese Patent Application Laid-open No. Hei 11-54270, in which 50 μm or more of slip occurs from the positional target of shot.